A new report from liberal think tank the Commonwealth Fund released on Monday ranks the United States health care system as the worst among 11 developed countries, but the report is deeply flawed.

The first giveaway that something is amiss should be the fact that the United Kingdom ranks as the top health care system of those studied. As I reported in a feature last fall, the U.K.'s National Health Service is facing severe problems and has been plagued in recent years by cascading scandals involving horrific neglect of patients. In U.S. policy debates, liberal supporters of single-payer health care have even backed away from touting the NHS as a model to strive toward in recent years, instead pointing to systems such as France, which offers relatively more choice.

The problem with the Commonwealth Fund study is that it’s rigged to produce a result that favors socialized health care systems. The study determines that the U.S. system is worse because it lacks universal health insurance coverage and the report emphasizes “equity” as one of the key factors in evaluating a health care system. But it’s an ideological decision to view equity as one of the most important factors in judging a health care system, just as it is for the study to leave out a factor such medical innovation, which would work to the advantage of the U.S., or choice, which would work against the centralized NHS.

The study also doesn't mention cancer outcomes. As it turns out, the U.S. ranks well ahead of the U.K. in five-year survival rates for 22 out of 23 types of cancers, according to data from the American Cancer Society.

The study also relies on surveys of patient satisfaction, which are subjective, because they vary based on people's expectations. If people have low expectations, then a system with objectively bad health outcomes could still be viewed as satisfactory.

In addition, the U.S. loses points in the study due to the nation's relative infant mortality rates. But infant mortality is a notoriously bad statistic for international comparisons, because it isn't consistently measured and varies by race and ethnicity. Racial minorities have higher rates of infant mortality, and the U.S. is more racially diverse.

This isn't to say that the U.S. has a perfect health care system. Even before President Obama's health care law, it was too costly and didn't leave consumers with adequate power. But the Commonwealth study isn't very useful for rating health systems as much as it is useful for understanding what liberals value in health care systems.